El Cajon is a city located in San Diego County, California, USA, 17 miles east of San Diego downtown. Located in a valley surrounded by mountains, the town has acquired the nickname "The Crate." The name derived similarly from the Spanish word "el caj?n," meaning "the box" or "the drawer." The site rancho Santa M?nica was first recorded as an alternative name on September 10, 1821, to describe the "boxed in" existence of the valley in which it stood. 1873 and 1875 the name appeared on maps.